Gold-PLated PCBs?

[Robert Baer]

Robert,
Silver has a limited lifetime. Is becomes black
from fingerprints (sulfur) and it is said to
become harder to solder when oxidized.

HAL is said to becoem hader to solder after a
certain time too.

Gold aparently is keeping fresh and solderable
for an unlimited time.

I never had any issues, also not with any I
came across. It might be the warnings come from
manufacturers.

I'm fine with silver. Gold costs 10% more.
Leadfree is no problem at all. I had to replace
my old Weller with a new one though. The old one
went through tips at an unbelievable rate.

Rene

Silver plate does not have a "lifetime" problem, it is a corrosion
problem (oxides and sulfides).
And there are inexpensive solutions: SilverSaver paper against board
in a sealed package; el-cheapo is mothballs with board in sealed package.

HAL does pick up oxides, so a simple sealing would suffice; additoin
of mothballs would extend safety.

These solutions appear to be viable for a year or so.

 

[Robert Baer]

In my experiences of long ago while working as a cal-lab tech and as a tech in
the Navy, I have noticed a significant number of equipment failures related to
gold-over-nickel plated terminals, soldering posts, component leads, etc. The
reason was that the gold would delaminate from the nickel and create an open
circuit, or even worse, an intermittent connection that was a nightmare to find.
After recognizing this problem, when I had to replace a component or terminal
that was gold-over-nickel, I would always heavily tin the gold area, then wick
away all the solder, taking the gold with it, before making the final solder
joint. And, if I noticed any joints that looked suspicious, I would always try
to leach all the gold away from the joint and resolder.
Never had a repeat failure by doing that.

Thanks for the sharing of your experience!

 

[Robert Baer]

They tell me that that black stuff (whether it's oxide or sulfate
or whatever) conducts almost as well as just plain silver.

But a little liquid silver polish will clean that right up. I don't
know if "Brasso" is abrasive, but if not, it would probably make the
silver look like new.

Cheers!
Rich

I assure that not only Brasso is abrasive, the other additives tend
to accelerate oxidation, etc unless cleaned extremely thoroughly.

 

[jasen]

They tell me that that black stuff (whether it's oxide or sulfate
or whatever) conducts almost as well as just plain silver.

But a little liquid silver polish will clean that right up.

I don't know if "Brasso" is abrasive, but if not,

It is. it's wax, abrasive powder, and some sort of solvent (kerosene?)

it would probably make the silver look like new.

they make "Silvo" for that.

not sure what's in it.

Bye.
Jasen

 

[Robert Latest]

It was common for old Tek and HP gear, roughly 1970 vintage, to have
pcb's with heavy gold plating everywhere, ususlly with no solder mask.
Nowadays, you see gold flash over nickel on high-density BGA boards,
or on boards that will be used with lead-free solder. We fabbed a few
boards like this recently... they looked like jewelry.

Yes they do! It's a shame to have to populate that nice board. But the vias
are still nice and golden.

robert